Film scratch minimizer



Aug. 2, 1960 n. s. HoRsLl-:Y

FILM SCRATCH lMINIMIZER Original Filed April 17, 1958 2 Sheets-Sheet 1INVENTOR.

DAVID S. HORSLEY BY @my .AGENT mn 5.5.23 nzoomuz v mums n rubi...QIDQNNZ Aug. 2, 1960 D. s. HoRsLEY FILM SCRATCH MINMIzER voriginal FiledApril 17. 1958 2 sums-sheet 2A HTL FIG. 4.

INVENTOR. DAVID S. HORSLEY BY fam AGENT United States Patent O FILMSCRATCH MINIMIZER David S. Horsley, 3929 Kentucky Drive, Hollywood,Calif.

Original application Apr. 17, 1958, Ser. No. 729,121,

now Patent No. 2,912,487, dated Nov. 10, 1959. Divided and thisapplication Jan. 12, 1959, Ser. No. 790,317

Claims. (Cl. 178-6.7)

My invention relates to electronic means for printing motion picturefilm and particularly for printing in color in a desired geometricalformat from an original film of different format.

This application is a division of my co-pending application entitled,Electronic Motion Picture Printer, filed April 17, 1958, Serial No.729,121, now Patent No. 2,912,487, granted Nov. 10, 1959.

With the advent of Cinem'ascope, Technirama, Panavision and otheranamorphised formats, and with the several film widths, as 8 mm., 16mm., 35 mm., 55 mm., 65 mm. and 70 mm., and with the 90 imageorientation of Vistavision, it will be understood that conversion ofpictorial information from one film format to another now transcends theversatility of optics and mechanics.

Accordingly, I have provided a universal electronic printer which iscapable of accepting an original film, either negative or positive, andprinting either a negative vor a positive in substantially any otherformat. This includes ninety-degree reorientation of the image, as fromVistavision to the more usual placement of the height of the image inthe direction of translation of the film strip.

This I accomplish by transporting the original film at uniform speed andscanning the same transversely with a white-light-emitting spot from afiying spot cathode-ray tube. The velocity with which the film istranslated is vregistered by photoelectric means coactive with selectedsprocket holes of the original film. The persistence of the cathode-raytube phosphor is, of course, very short. 1t will be appreciated thatthis processing can be carried vout at standard television repetitionspeeds, though it 'need not be. I prefer to operate at from one-'half toone-eighth such speeds in order to obtain increased resolution. Anoptical system reduces the image size of the cathode-ray tube spot onthe original film by a factor of 'the order of four, thus the requiredsmall spot of light upon the film is obtained.

Behind the original film at least two dichroic mirrors coact with threephotomultiplier tubes to provide three :simultaneous video signalscorresponding to primary 'colors or Ithe equivalents thereof. This isnormally red, `green and blue transmission and reflection 4by suchfilters as will be later explained. Separate amplifiers amplify each ofthese signals.

An electronic computer, in the form of card and tape readers, connectsto the flying spot cathode-ray tube to determine the intensity of thespot thereof for fades or `the accommodation of different densityoriginal material, the position ofthe scanning traverse transverse ofthe original film, the extent of the traverse and whether it betransverse of the film as usual or longitudinal of the `original film inone manner of re-orienting Vistavision iframes. The computer readers arealso connected to the 4separate amplifiers to control the individualgains, gamma and other functions in order to compensate for color-unbalance in the original film and for other reasons.

For exposing unexposed color film, means are provided within aIlight-proof enclosure to transport the lm at a 2,947,810 Patented `ug.2, 1960 ICC speed analogous to that of the original lm. Color televisionimage reproducing means optically infiuence said unexposed film througha reduction optical system in the same manner as described in connectionwith the original film. Through a servo control the electrical outputfrom a photoelectric means coacts with the sprocket holes of theoriginal film to regulate the relative speeds of the original and theunexposed films. These speeds may be the same for 35 mm. to 35 mm., butquite dierent for 35 mm. to 16 mm. or for other changes in format. Cardsand paper or magnetic tape program the readers. The cards determine theparameters fixed from conversion of one format to another and the tapethe running instructions according to the characteristics of theoriginal film land those desired in the new print.

An object of my invention is to provide a motion picture film printercapable of converting film from one format to another over a wide rangeof formats.

Another object is to provide an electronic printer having greaterflexibility in obtaining desired characteristics in the print than hasbeen heretofore possible.

Another object is to provide a television-like picture of the processingfrom original to print while such processing is taking place.

Another object is to vary the density range of the reproduced film withrespect to that of the original film by an electronic signal controlwhich does not alter the intra-range gradations of density.

Another object is to accomplish increased resolution in film printingover that obtained in television broadcasting operations by operatingthe apparatus more slowly.

Another object is to obtain accurate image registration by electronicmeans.

Other objects of my invention will become apparent upon reading thefollowing detailed specification and upon examining the accompanyingdrawings, in which are set forth by way of illustration and examplecertain embodiments of my invention.

Fig. 1 shows the general layout of my electronic printer;

Fig. 2 shows the detail of a multiple lm size sprocket;

Fig. 3 is a plan view of an alternate embodiment of sprocket holeregistration optical system;

Fig. 4 shows a greatly enlarged front elevation of a film sprocket holeand a mask optically coactive therewith; and

Fig. 5 shows an electrical pulse waveform resulting from the coaction ofFig. 4.

In Fig. 1 electronic elements are given in block form, mechanicalelements in simplified form with no showing of obvious mountings andoptical elements in proportion but of simplified representation.

In Fig. 1 number 1 indicates a high-intensity highvoltage cathode-raytube having a rapid decay phosphor and forming the essential element ofa modified flying spot scanner. The RCA type 5AUP24 tube having aphosphor with a 10-8 second decay, or faster, or the Du- Mont K1347 tubehaving a P15 phosphor are suitable available examples. It is operated ata high voltage of many thousands of volts and is provided with knownelectron focusing means.

Horizontal and vertical deflection yoke 2 deflects the electron streamof the tube 1, the stream being formed by electron gun 3. Horizontalsweep 4 produces sawtooth waveform scanning energy and is connected toyoke 2.

By scanning at less than usual television speeds I allow more time forphosphor decay in relation to the distance traversed and so secureincreased resolution. The frequency of the sawtooth scan of sweep 4 isthus arranged to be adjustable over the range of from one-eighth toone-half of the standard television frequency of 15,750

www

cycles per second. The frequency chosen is determined by a punched cardinserted in card reader 5 for the particular run. The card reader andsweep are connected by conductor 6 to effect this control.

Transverse film scanning is VVaccomplished by the horizontal sweep butthe longitudinal'scanning thereof is accomplished by motion of the filmitself. Accordingly, a vertical scanning sweep in the usual sense is notprovided, but a vertical adjust scanning waveform source 7 instead. Thissource is direct coupled to yoke 2. by conductor 8. Y

This allows a permanent vertical adjustment of the rapidly horizontallydeected .liner of light on the face of cathode-ray tube 1 and acorresponding adjustment in the Yinverse direction upon the film to beprinted. Also, when the aspect ratio of theprint is to be diiferent thanthat'of the film original the vertical adjust electronic source providessawtooth deliection energy in the direction o f the film motion to readthe film more slowly or more rapidly than corresponding to its motion.In this way the framevlines are either decreased or increased in widthin the print.

y When it is necessary to reorient Vistavision scenes from the side byside position thesefoccupy in the Vistavision format to the more usualformat of one scene above the other along the film strip it is necessarythat the scanning accomplished by cathode ray tube 1 be orientedvertically, in line with the length of film 9, rather than horizontally,or transverse thereto. This is not accomplished by turning the tube, butby turning the yoke by 90. The yoke therefore has a quadrant 10 providedwith gear teeth and a worm 1 1, externally supported, which engages thegear teeth. The worm is rotated by rotary actuator, or motor, 12. Thelatter is connected to card reader 5 by conductor 13, from which apunched card determines whether the normal or the 90 rotated position ofthe yoke 2 shall be used for the particular processing run. Twoadditional waveforms are supplied to the yoke to accomplish `Vistavisionscanning as willbe detailed below.

It is desirable that the return traces of both deection elements 4k and7 be eliminatedl from the trace of the uorescent spot on the face ofcathode-ray tube 1. This is accomplished by conveying a negative pulseformed as the first derivative of the sawtooth waveform, or otherwiseformed, from sweep 4 to the control grid of gun 3 of the cathode-m1.Vtube via conductor 14 and from adjust unit 7 via conductor 15.

Because only a line of light is employed across the cathode-ray tubescreen rather than a full area raster as is conventional, I providemeans totilt the tube slightly without correspondingly tilting the yoke2, which latter has al slightly oversize inner hole to allow thismechanical manipulation. The tilting is accomplished byv a slowmovingeccentric actuator 16. This element is actuated from card reader 5 viaconductor 17. Because a slight inclination of the cathode-ray tube willalso slightly inc line the gun 3 thereof, a slightly, different biasfrom adjust 7 is required. These compensating functions are carried outby reciprocally placed punches'in the card of `the card reader 5. Y

The wavy element 1ST directly in front ofthe face of cathode-ray tube l1is a schematic representation of a light filter. The wavy shape of thes'chemati`showing isA not necessary in the actual structure of thefilter, which is preferably planar. This filter is provided to allowalteration of the spectral response of thecathode-ray illuminating spot.With such it is possible to not `only correct for spectral deficienciesin the spectrum ofthe fluorescent spot but to alter therendition'of'the'fllm'D 4as Vdesired in the color sense.Plural'ifiltersV 18 may be employed,

hue to strengthen the relative red emission of the light from tube 1.

Lens 19 is the objective lens of the optical system and serves to form areduced image of the fluorescent spot of tube 1 upon the film 9. This isto be noted by the greater distance from tube 1 to lensf-19 than fromlens to film 9. The size of the light spot on the cathode-ray tube is ofthe order of j/10 millimeter in diameter. The ratio of the Vfirst to thesecond distance mentioned is conveniently four to one. One thousand linedetail is obtainable per frame of usual motion picture film. 'This isclose to the inherent resolving pow'er of the emulsion and well withinthe allowed unsteadiness' of theatrical motion picture projectors.

The system of Fig. 1 is for producing three separate primary colorsignals, corresponding t'o three (monochrome) color separation negativesin conventional printing. The color separation is achieved by dichroicor equivalent mirrorsl 29 and 21. These are positioned behind the filmV9 where the Yspot of light will be intercepted and are arranged like aroof with a included angle. Mirror 20-is constituted to reect red lightand to pass green and blue. `Mirror 21 is constituted to reflect bluelight and to pass green light. The process for making these dichroicmirrors is well known. It is also known that such mirrors effect arela'- tively sharp and complete separation between the three primarycolors; For obtaining color information from a negative film at 9 evennarrower bands than obtained with the dichroic separation desired. Thus,for filter 2.2 a Wratten No.V 29V is used to pass the red desired. Forlter 23, Wrattens No. 47B plus 2B are used to pass the blue' desired.For filter 24, Wrattens No. 16 plus 6l are used to pass the bandrepresentative of green desired. -ln instances where nlm 9 is a colorpositive such sharp separation may'not bel desirable. This is because aless definite color separation often gives an improvement in the'colorrendition. For the rst mirror 20 we now eniploy a quarter-silveredmirrorV deposited on thin glass instead of a dichroic mirror to reflectthe illumination upward and for the second mirror 21 a quarter-silveredmirror instead of a dichroic to direct the light downward. The Wrattenfilters provide all the color separation in this modification. Red pathfilter 22 and Vblue path Vfilter 23 remain the same but the green pathfilter 24 becomes Wratten No; 56. These lters would be infrequentlychanged in the usual run of processing so automatic means for changinghave not been provided.

Directly beyond each filter mentioned is one of three de-motionalizinglenses'25. These image the cone lof illumination from objective lens 19upon the sensitive surfaces of corresponding photomultipliertubes 27,28, 29, which convert the red, green and blue illumination to'electrical signals. Lenses 25 cause a defocussed area of light toimpinge upon each sensitive surface in a motionless pattern regardlessofthe motion of the Vspot in the plane of the film. This is desirable inpreventing spurious signals arising from variation of sensitivity. overthe sensitive surface.

Photomultiplier tube 27 preferably has a red-accented characteristic andmay be the RCA 7102 type with an S-l spectral response. Photomultipliertubes 28 and 29 have a substantially uniform green and blue response andmay be the RCA 6217 Ytype with S- lO spectral response. These knowntubes contain an electron multiplier of ten'rnultiplying stages, eachhaving a secondary emission ratio reasonably greater than one. Anoverall accelerating potential of the order of 1,000 volts providesamplification of the minute photoelectric currents of hundreds ofthousands of times.

Each of the photomultiplier tubes is followed by one or more stages ofconventional video amplification as represented schematically byamplifiers 3i), 31, 32. These bring each signal level to an amplitude ofseveral Volts, and. s0 make .Convenient the operativa Qf the reboundlimiters for each of the' primary color channels. These limiters, 33,34, 35, are of essentially identical construction and are included toremove the elects of scratches on the original iilm upon the printobtained from my apparatus.

It will be understod that the opacity of clear film is considerably lessthan the lightest opacity of any ordinary scene. Correspondingly, theamplitude of the video signal corresponding to a scratch in the iilm isgreater by a like amount. By the simple process of setting an overloadclipping level on the video signal the disturbing effect of theotherwise bright reproduction of the scratch is reduced. However, withmeans to reduce the amplitude of the video signal corresponding to thescratch to a value approximating the average value of opacity of thescene I am able to largely remove its presence. It will be appreciatedthat this capability is valuable in reproducing historical film, fromnegatives from which many prints have previously been made, and frompositives that have been exhibited a number of times but whichconstitute the only source of iilm material available.

I am able to reduce the scratch video signal to an average value byutilizing the energy of the initial rapid rise to actuate an averagelevel setter of short duration, which duration is terminated by thereverse throw of the initially abnormally high scratch amplitude. Thelevel setter may take the form of a bistable multivibrator, oneequivalent signal level of which is at black level and the other isbelow that level by nearly the full contrast range of the signalchannel. When the latter is combined with the overload signal the resultis in the average contrast range. The leading edge of the scratchtransient triggers the multivibrator from the black level and thefollowing edge of the scratch transient returns the multivibrator signallevel to black. In this way I am able to restore the damaged scene to aneutral value in which lthe defect is largely unrecognizable. Thefrequency capability of the multivibrator must extend to a fairly highvideo frequency in order to handle narrow scratches. It will beunderstood that this rebound limiter will also essentially remove clearfilm spots brought about by defective prior processing or cue markswhich have been scratched upon or cut through the film base. Bistablemultivibrators per se of the required frequency capability, such as thehigh speed Eccles-Jordan flip-flop, are packaged articles of commerce inthe computer industry. Accordingly, this circuit is not furtherdiscussed here.

The next group of video elements in the three separation chains ofapparatus consists of variable gain and gamma amplifiers 36, 37, 38.These are connected to accept the output from the appropriate reboundlimiter and are also connected to tape reader 39 by conductors 40, 41,42. The tape reader coacts to exercise continuous control over thefunctioning of the apparatus and will be further described later.

It will be understood that the overall contrast ratio of the scenesprinted by my apparatus may be increased by increasing the amount ofvideo amplification over what is easily empirically determined as anequivalent contrast ratio to the original iilm, and that the inverse istrue. It will be further understood that the intra-range contrast ratiocan be changed as may be desired by altering the shape of the transfercharacteristic of an amplifier stage of the video amplifier; i.e., agamma correction stage. For example, the reduction from linear variationof density occasioned by an overexposed negative or original print atlow densities (bright portion of the image on the llm), may becompensated for by a vacuum tube stage having approximately anexponential characteristic; i.e., a larger grid bias than usual, so thatthe curvature of the transfer characteristic reproduces the higherdensities at a reduced value and the lower densities at an enhancedvalue. This causes the transferred characteristic to approximate astraight line.

Both variable gain amplifiers and gamma amplifier stages (having anon-linear transfer characteristic) are known to the video amplifierart. In further explanation of the above example of the expansion of thecontrast range in the highlights reference is made to the Orthogamamplitier of Goodale and Townsend and the inverse by the rooteramplifier, both illustrated and described in the book, Television, byZworykin and Morton, 2nd edition, 1954, pp. 524-526. (Wiley).

The control over this portion of the system by tape reader 39 goes towhich type of correction ampliiier is switched in circuit and whatdegree of overall amplification is chosen for any particular portion ofthe film being reproduced. It is apparent that with suchinstrumentalities shortcomings in the original film can be largelyremoved from the print and that this may be accomplished on ascene-to-scene basis throughout the original because of the co-phasedcapability for modification afforded by the tape reader.

Subsequent to the recited elements, further video amplifiers 43, 44, 45are connected to elements 36, 37, 38 in order to bring the signal levelto a few tens of volts in order to properly control the intensity of theelectron beams of reproducing cathode-ray tubes 46, 47, 48. Theconnections from the video amplifiers to the cathode-ray tubes are madeto the control grid or to the cathode of the guns for each tubedepending upon the positive vs. negative phase of the image desired uponthe cathoderay tubes or for secondary reasons of circuit design known tothe video art. Normally, the phase relation throughout the whole systemis arranged to provide a positive print from a negative 9. By merelysupplying a positive print for lm 9 `a negative print can be obtained.By switching in or out an additional phase-reversing stage under thecontrol of the tape reader located in the variable gain and gammaelements a positive may be obtained from a positive or a negative from anegative.

While a color image reproduction could be formed by a single tricolorcathode-ray tube, such as the known shadow-mask type, I prefer to employthree separate cathode-ray tubes as shown. This allows greateropportunity for obtaining color balance under both usual and correctiveconditions and for making other incidental adjustments to the image thatexposes print 52. This latter film travels uniformly, as did film 9.Consequently, only line images are formed on each of the cathode-raytubes 46, 47, 48, rather than complete images over raster areas as inusual television reproduction.

The matter of Vistavision orientation of prints is present in theprinting operation as much as in the reading operation previouslydescribed. Thus, reproducing yokes 53, 54, 55 are constructed, mountedand provided with gear segments 56, worms 57 and actuator 59 as were thepreviously described yokes. The latter actuators are connected byconductor 60 to card reader 5 for appropriate actuation according to thepunchings upon the card within said reader. Similarly, the matter ofvertical adjust is provided by a separate conductor 61 from verticaladjust element 7. The adjustment upon conductor 61 is under the controlof card reader 5 and tape reader 39 over separate control conductorswith respect to that for reader conductor 15. The control conductors forthe reader control are 62 and 63 from card and tape readers,respectively, whereas the control conductors for the reproducingconductors are 64 and 65. The actuation of these orientation controlsmay frequently be the same for reader cathode-ray tube yoke 2 and forthe group of reproducing yokes 53, 54, 55, but since corrections to agiven format and different formats are possible with separate controlsthese are provided in this instance and elsewhere in my apparatus tolend universality to it.

In a further similar manner slow moving eccentric actuators 66 servetotilt the reproducing cathode-ray tubes in the same manner as utilizedwith actuator 16 previously described. This control is exercised fromcard reader over conductor 67 andis independentof earlier controlLconductor 17.

In order that independent color co'rrt'ectionV maybe ac-l complished forany set of conditions, separate Wratten or equivalent filters areprovided-in front of each reproducing cathode-ray tube. Filter 68,normally having a reddish hue, is placed in front of the red-reproducingcathode-ray tube 46 to enhance the spectral pur-ity of the redV phosphorthereof. Wratten filters Nos 16 plus,l 61 are suitable. Filter 69 is infront of the green cathoderay tube 47 for color balance purposes' uponthe green light-emitting phosphor thereof. A Wratten No. 47B filter issuitable for this purpose. Filter 70 is similarly in front of the bluelight-'emitting phosphor cathode-ray tube 48 and a Wratten No. 29 lteris suitable for this position.

An arrangement of dichroic mirrors is positioned in front ofthe threereproducing cathode-ray tubes 46, 47, 48. Dichroic mirror 72 reflectsthe red light from tube 45 and passesrboth green and blue. Dichroicmirror 7l passes green light and reflects blue light. In this way thecomplete line color image is formed in front of objective lens 73. Thislens is axially adjustable in mounting 74, which in turn is supported inlight-tight housing 7S. The optical paths from the three cathode-raytube screens to the lens 73 are of equal length. Accordingly, thecomposite image of the line image is accurately focussed in a reductionratio of at least a few times upon unexposed film 52.

In order to remove the horizontal squeezing of anamorphised originalfilms when non-anamorphised prints are desired, the ratio of horizontalto vertical scan at the writing (reproducing) end of the process isincreased. That is, the horizontal scans at both reading and writinginstrumentalities cover the normal width of the film, but the effectivevertical scan is decreased by vertically moving the line of light onscanning cathode-ray tube 1 in the direction of the motion of film 9during the scanning of an image andV returning it during the frame lineinterval according to a sawtooth waveform. Alternately, the horizontalscan of tube lis decreased in amplitude. This reduces the width Aoftheimage printed from the original film but renders it in thenormalheight-width ratio on the print.

Additional special effects, such as to remove or impose non-lineargeometry in the print, may be introduced horizontally by correspondingnon-linear sawtooth waveforms employed for the horizontal scan of eithercathode-ray tube 1 or the group 46, 47, 48. Alteration of verticallinearity is accomplished by employing a non-linear vertical adjustwaveforin from element 7 upon cathode-ray tube 1. Otherwise linearsawtooth waveforms may be made non-linear in elements 4 and 7 byaltering the time `constant of the circuit forming such waveformsor bycombining a linear waveform with a curvilinear waveform of the same or aharmonically related frequency and of fractional amplitude with respectto the amplitude of the sawtooth. i

We now turn to a consideration of the film transport mechanism. Originaliilm 9 (which may be a negative or a positive) is unwound from aconventional storage reel (not shown) and passes over required guiderollers, of which roller 77 is illustrative. This roller is preferablypreformed'to accommodate 8 mm., 16 mm., 35 mm., 55 mm., 65 mm., and 70mm. film in the manner of the sprocket of Fig. 2, or a series ofindividual or partially universal rollers may be substituted tohandle-'the particular nlm to be processed.

A flrn gate is positioned opposite lens 19 to insure that the film 9shall always remain in the focal plane of that lens. This gate isconventional and has not been shown for sake of clarity. Sprocket 78 isthe drive sprocket for film 9. It, too, is relatively close to the filmgate. It is formed to handle various widths of film as will be describedlater. The sprocketV is attached to the shaft of image geometry will beuniform from frame to frame,

q particularly upon the resulting print `52. This synchronis'rn can beaccomplished by meansV of the synchronizing generator used withtelevision cameras for maintaining. a fixed ratio between horizontal andvertical scanning frequencies. Such a synchronizing generator isdescribed' inthe book, Television, by Zworykin & Morton, 2nd edition,1954, pp. 594-596 (sec. 14.10) (Wiley).

The generator is essentially a frequency dividing circuit. The high(horizontal) frequency is stabilized by a piezo-electric crystal and thelow frequency is syn` chroniz'ed from the highv frequency counted' down.In. the present application the low frequency corresponds to that ofselsyn 79 and this is driven by a high power electric amplifier havingthe counted down frequency as an input.

A preferred alternate makes use of the stability of the 60 cyclealternating current power system. The counted down frequency from thesynchronizing generator is electronically compared with the alternationsof the 60 cycle wave and a bias potential is formed which varies withany frequency variation of the high frequency scanning sweep. This biasis applied to the high frequency sweep (4) to counteract the frequencyvariation.

In the apparatus of Fig. l the frequency dividing circuit is a part ofservo control S7. In the preferred alternate the power motor ofconventional design forming a part of the selsyn unit 79 is of thesynchronous type of good angular phase stability. As before, the selsynpart serves to generate alternating current to drive the similar unit ofthe other film 52 in strict synchronism. In this manner the motion ofthe two films 9 and 52 and the spots of light which scan them are heldin a unified synchronism. This whole system is actuated in preciserelation to indexed perforations on film 9 by sprocket hole registrymeans to be later described.

After passing sprocket 78 film 9 is wound upon a takeup reel known tothe art and therefore not shown. I have employed constant torque motorsfor the unwind and takeup functions to provide a uniform tension on thefilm while it is in the film gate regardless of the amount of film uponthe reels involved. V A sprocket hole register optical system is shownabove motor '79 in Fig. 1. This system includes in order in the opticalpath, incandescent (or equivalent) exciter lamp Si), a pair ofplano-convex condensing lensesl 81, film 9, further condensing lenses82, and photoconductive or photoelectric cell 83. This optical system isarranged to give a sharply defined spot of light smaller than the sizeof the well-known sprocket holes in the motion picture film. Thedifference between the opacity of the clear film base and that of a freeairpath through the sprocket holes is sufficient to give a modulation ofthe light received by cell 33. This modulation is converted to anelectric current by the cell and is amplified by amplifier S4 to a levelofa number of volts.

It is not widely known that only certain perforations in a strip ofmotion picture film are accurately indexed to the image that has beeneither photographed or printed thereon. This is vknown to the specialeffects art, where unusual accuracy in image registration is required.In the Mitchell type of registration the sprocket hole just above thepicture on the sound track side is the sprocket hole that was fullyregistered when the film was exposed in the original camera or in asecond special eifects camera by an in and out camera registry pin. Thisarrangement provides both longitudinal and lateral placement. Directlyopposite this perforation another sprocket hole was pin registered so asto give proper longitudinal orientation but the pin associated therewithhad a few thousandths of an inch free space on each side of theperforation to accommodate shrinkage or other variations in the film. Inthe Bell & Howell 170 registration the same situation obtains, save thatthe register perforations are just below the frame in question and onthe sound track side for the full registry pin as before.

In Fig. l it has been necessary to show the sprocket hole registerentity 80-83 below the picture optical system 19-20, etc., in order toavoid serious drafting confusion. However, as will be understood fromthe above description the subject entity is actually mounted adjacent tothe optical system 19-20'as shown by the asterisk It is provided with anadjustable mounting to position the optical path either above or belowthe film frame being scanned for optical picture information. This is sothat Mitchell or Bell & Howell registrations may be duplicated inprocessing by my machine. Card reader controls which position themounting shall take by an electrically controlled mechanical adjustment.

Any previous attempts to control film movement by registration with thesprocket holes optically has employed all the holes down one side of thefilm. vIt is apparent from what has been explained above that a controlof this type is seriously lacking in precision.

For this reason I employ perforation register gate 85. In acharacteristic adjustment this circuit allows only every fourth pulse topass to the output. Connection 86 from the green separation amplifier 31provides information as to where the picture is located on the tilm withrespect to the frame line. The passage of a frame line in front of thepicture scanning spot causes an absence of video signal as will beeasily understood.

Gate 85 is essentially a multivibrator circuit which has an o periodthree times as long as an on period, as above adjusted. The gate issynchronized on by the absence of video signal as above mentioned andautomatically blocks olf the circuit thereafter due to its inherentip-op nature and period. The output from gate 85 is conveyed to servocontrol 87 over conductor 88. As has been described the servo control isconstituted to move both the reading film 9 and the writing lm 52 insynchronism. The sprocket hole registry information adds precision tothis control. Information concerning the exact electrical nature of thesynchronism for films of different formats (as 35 mm. for film 9 and 16mm. for film 52) is conveyed to the servo control from tape reader 39via conductor 89. Servo synchronization for the second servo motorassembly 90 is conveyed from servo control 87 via conductor 91. In thiswriting portion of my printer roller 147 is the equivalent of roller 77previously described and sprocket 92 to previous sprocket 78. A filmgate 93 is employed to guide the film 52 at the focal point of lens 73in the same manner as a gate was employed previously for film 9.

It is highly desirable, although not necessary, to present a monitorimage to the operator, by means of which he is enabled to check theoperation of the major portion of the apparatus.

This is accomplished by providing color cathoderay tube 94, which may beof the known shadow-mask type having three electron guns. One of theseguns `is connected to the output conductor from red channel amplifier43, another correspondingly to green amplifier 44 and still another toblue amplifier 45.

A d'eection yoke 95, adapted for both horizontal and vertical deectionof the electron beams from the three guns, surrounds cathode-ray tube94. Horizontal deflection is accomplished by sawtooth scanning energyfrom horizontal sweep 4 via conductor 96. A separate vertical sweeposcillator 97 is provided. This operates in accordance with the verticalspeed of film 9 and synchronizing information comes from `servo control87 via conductor 98. The horizontal sweep is also appropriatelycontrolled to lgive an equal number of scans across the film orcathode-ray screen regardless of the speed of traverse of the film 9.This control is from tape reader 39 via a report-back connection 99 fromservo control 87. This control insures that the number of lines perframe upon film 52 shall also be the same regardless of the longitudinalspeed of that iilm.

Assuming that a color film 9 is being processed, it is apparent that thecolor television image presented upon color cathode-ray tube 94 providesa check upon the operation of all parts of the system save that of thereproducing tubes 46, 47, 48 and the exposure of lm 52.

In order to indicate the relative signal levels in the three channelsfor color balance purposes Waveform cathode-ray Oscilloscopes SSR, SSG,58B are provided. The vertical deflection means of oscilloscope SSR isconnected to the output of red output amplifier 43. Oscilloscope 58G issimilarly connected to the green output amplifier 44, and oscilloscope58B is similarly connected to the blue output amplifier 45. Thehorizontal deflection means of each tube is connected to vertical sweep97. As a consequence, the video signal of each color component channelis shown. These are compared with reference marks provided upon atransparent overlay 145 which indicate the signal amplitudescorresponding to an important color such as flesh tome. A deficiency orexcess in the color primaries will be noted and appropriate adjustmentof the contrast or brightness may be made in the variable gain and gammaamplifier of the channel involved. The need for these adjustments may benoted in a trial run of film 9 only and the tape of tape reader 39appropriately re-punched for the subsequent processing run.

It is important to note that in my electronic printer both contrast andbrightness of any or all color component channels may be varied, whereasin printers of the prior art only brightness could be variedVas byvarying the brightness of the printer light. Accordingly, not only can aproper liesh tone balance be struck electronically and a consistentneutrality attained in the rendition of hueless gray, but limitations ofcolor film emulsions can also be overcome.

Contrast in the blue primary is often poor in rendering flesh tones.Because of imperfect behavior of the yellow dye in some color film anadditional yellow is deposited in response to blue stimulation. Thisresults in flesh tones of salmon hue. Such a condition is at onceremedied by adjustment of electronic controls as has been indicated.

Waveform Oscilloscopes 58R, 58G, 58B have been shown by way of exampleconnected to the output circuits of the electronic portion of myprinter. These may be switched by obvious known switching means to theinput of the electronic portion; i.e., the outputs of linear channelamplifiers 30, 31, 32. This allows inspection of the color balance ofthe original film and is useful in a trial run of film 9 to originallydetermine what instructions are to be punched' in the tape of tapereader 39.

As has been mentioned, there are a number of film formats in use todayand the perforation registry of each is more often different than thesame in relation to film length. The four perforation per frame examplegiven corresponds to 35 mm. film of the long-standing format and alsofor Cinemascope in the 35 mm. version. However, Cinerama film, although35 mm. in width, utilizes 6 perforations per frame. Accordingly,conductor 95 connects from card reader 5 to perforation regi-ster gateto alter the time constants of the multivibrator circuit thereof. Whatis required is that the time constant of the gating waveform throw thatopens the gate be reduced in duration and the time constant of the samethat closes the gate be lengthened. This is brought about by decreasingthe resistance of the time constant circuit for opening and byincreasing the resistance of the time constant circuit for closing. Thiscan also be accomplished by similarly altering the effectivecapacitances of the time constant circuits, or the change of bothresistance and capacitance. These alterations are accomplished throughconductor 95 actuating known relays in the gate entity 35 to effect thetime constantV changes mentioned.

Each of the labelled conductors shown in Fig. l, as 6, 91,Y 95, etc., iscomposed of at least a plurality of separate insulated wires. In thisway plural functioning over one conductor as illustrated isaccomplished. The conductor establishes the existence of a wiredcommunication channel from one block element to another. In Fig. l theextent of the plurality of separate circuits is made evident by thedescription of the circuitry of the blocks involved.

In further respect to formats, Vistavision has 8 sprocket holes perframe, with the image twice as Wide as usual and lying with the widththereof in line with the length of the lrn strip rather than transversethereto which has been standard for a long time. ln order to properlygate Vistavision iilm the duration of the pass gate pulse may remain thesame as for usual 35 mm. film but the duration of the off gate pulse isslightly more than twice as long as for the usual 35 mm. film.

A 55 mm. lm, as currently produced by the 20th-Century Fox company, has8 perforations per frame on the negative and 6 perforations per frame onthe positive. The height of each of these films per frame is `differentand both are greater than the height of the usual 35 mm. frame.` Thusthe total period of a complete cycle of the'gate must be longer than forthe usual 35 mm. lm, with this being greatest for the 55 mm. negative.Because of the greater number of perforations in'the'negative the passinterval must be shorter than for the positive. This alteration, and thealteration of both of the blocking intervals is easily accomplished forautomatic punched card control as taught above.

A 65 mm. positive lilm for theatrical release is employed by theTodd-A0. format and by MGM. It has perforations per frame. The height ofthe frame is also different from that of the 55 mm. film, being less. Apass interval somewhat longer than that for the 55 mm. lm is requiredand the blocking interval is easily determined by a comparison of thegeometries.

A 70 mm. wide lm isemployed by the above-mentioned organizations fornegatives, and for daily inspection prints made by contact printingheretofore. Five perforations are used per frame and equal frame heightdoes not require any change in the gating with respect to that for the65 mm. lrn.

For 16 mm. lm there is only one perforation per frame and this, ofcourse, is employed for registration. Accordingly, a gating function isnot required andthe gateis held open by a continuous potential suppliedfrom or controlled by card reader 5.

Eight millimeter film also has only one perforation per frame and so thegate is also held open by thecontinuous potential referred to.

In the several above formats the accurately timed register pinperforation pulse passes to servo control 87 via conductor $8 and theresynchronizes by electrical comparison the servo frequency which drivesthe selsyn system. The servo frequency is the same throughout the systemwhen films of the same format are used for both 9 and 52. When these arenot of the same format, as from a 35 mm. negativeto a 16 mm. positivefor reissue of a motion picture to television, electrical modificationis introduced which drives motor 90 at the speed proper for v16- mm.although .the register perforation pulses originate frorn13`5 mn:i..i1m.

Thismodication also takes into consideration the different: diameterdrive sprockets and thus the different numbers of frame driven perrevolution of the sprocket. While, the perforation per frame parameteris xed by the format the relative diameters of the drive sprocket forthe different formats is a more or less independent parameter. In thisway selsyn frequencies which are either multiples, or submultiples ofthe frequency originally created may usually be used. A frequency twicethat generated may be obtained by known frequency doubler means, eitherof the resonant circuit or of the rectiler type. A frequency half thatgenerated may be obtained by known frequency dividers, as bymultivibrator or counter circuits. Should non-harmonic frequencies berequired, these may be electromechanically produced by linkingmechanically selsyn motors and generators having an irrationally relatednumber of poles.

A detailed view of a universal format drive sprocket, such as used at 78and 92 in Fig. l, is shown in Fig. 2. ln each step for Wider lm thesprocket' diameter is greater so that the wider iilm does not contactthe teeth of any of the narrower widths. Thus, the inner diameter issufficiency wide for eight millimeter lilm and has a minimum of fourteeth 101 so that one tooth is always in contact with the iilrn for theusual degree of wraparound of the tlrn upon the sprocket. These teethare foundon only one-side of the sprocket because the-8 mm. film isperforated on only one side.

The next larger diameter has one flange 102 with an increased number ofteeth, as six, and is for 16 mm. iilm. A companion opposite flange 103is of equal diameter but is without teeth since the sound track of 16mm. lmis on the-side opposite the sprocket holes. Similarly, anges 104and 105 of still larger diameter and each having eight teeth accommodate35 mm. film. Still larger and farther separated flanges 106 and 107,having twelve teeth each, accommodate 55 mm. lm. Finally, still largeranges 108 and 109, having sixteen teeth eachgaccommodate 65 mm. film.

The stilll wider 70 mm. film is accommodated by arranging outergflangev108 to slip axially on an inner hub 110 in anoutward direction adistance of- 5 millimeters; Spring ball detentsV (not shown) arearranged on hub 1.10 at the 65 and 70 mm. positions. The flange 108: isthen manually shiftedv from one relatively locked position to the other.

For automation the detents are omitted and flange-108 permanentlymagnetizedV with a pole upon they outer (left) face. Anelectricalcoil,lllhavingf circular turns of wire in vplural layers isdisposed-stationarily adjacent to ange 108 and coaxial therewith. Thiscoil is energized with direct current in oneY direction and a pole isproduced in inner pole piece 112 in polarity opposite to-that of flange108. Flange 108 is thus` attracted andthe sprocket is suited for 70 mm.lm. When the'coil is energized with current in the opposite direction apole of the same polarity as that of flange 108 isproduced andthe flangeis `repelled. This suits the sprocket for 65 mm. lm. A suflicientmagnetomotive force to solidly position flange 108 in` either the70 orthe 65 mm; positionagainst mechanical stops is easily arrangedwith acurrent of a fraction of an ampere. Mechanical drive of flange 103 isprovided by key y113:. This is held in hub 110 and has ansliding titslot in theinner hole of the flange.

The sprocket hole registry-optical systemtl, 81, 82, 83 illustrated inFig, l is capable of refinement as shown in the plan view of Fig. 3.

A source of illumination 115, substantially as before, is provided witha pair of condensing lenses 116 to illuminate restrictive horizontalslit aperture plate 117. Objective lens 118 forms an image of theaperture plate on film 9. The light path is bent 90 by right angle prismV119. The latter is employedV to mechanically offset the opticalsystemfor the sprocket hole registration at the light gate wheretheltelevision-like scanning offthe picture 13 upon the lm takes place.In this way the elements of the two light paths do not interfere.

After passing through the perforations in the film the light from thesprocket hole registry optical system impinges upon a second right angleprism 120 and is again bent 90, traversing a parallel but opposite pathto the original one. Lens 121 collects the divergent illumination thatwas focussed at the film. This illumination then strikes photoelectriccell 122. A photoemissive cell has been diagrammed, but this may also bea photo-conductive cell such as cadmium sulphide or selenium. For theselatter the illumination must be relatively high, above 60 foot candles,so that 'the response time of the cell is sufficiently rapid. Aphotomultiplier type of photoelectric transducer may be substitutionallyemployed, of course.

The Well-known Bell and Howell perforation has arcuate sides. I employthis feature to give a relatively very sharp light pulse which indicatesthe position of a given perforation with respect to the position of anoptical system of the types described.

Fig. 4 shows a greatly enlarged view of one sprocket hole 124 in dottedrepresentation behind an optical mask 125 which covers most of it fromthe light path of the optical systems mentioned. Two aperatures 126 and127 are formed in mask 125 at substantially the maximum width of thesproccket hole. Mask 125 is positioned longitudinally of the film and inrelation to the scanning line traversing the image upon the film so thatthe relation of apertures and sprocket hole shown in Fig. 4 occurs whena registry hole is in the position of registration in my printer.

As film 9 moves downward, for instance, to the position shown in Fig. 4,it will be seen that the light flux passed by apertures 126 and 127 willincrease from zero to a maximum value when the greatest width of theperforation is directly opposite the apertures, and that theillumination will decrease again to zero according to the same functionthat describes the increase. In addition, lm 9 has a finite thicknessand relatively smooth inner surfaces of the curved Asides of thesprocket hole. This causes a specular reflection from the sides of thesprocket hole the light from which is collected by lens 121 (Fig. 3) andpassed on to photocell 122 when the film is exactly in the registryposition. In other positions of the iilm any such reflection is directedin such a direction as not to enter the photocell. y

The illumination through the apertures and thus also the electricalwaveform from the photoelectric cell 122 as above described isillustrated in Fig. 5. The voltage across the output resistor associatedwith the photoelectric transducer is plotted vertically as the ordinateand the horizontal abscissa is time. Only a passage of one sprocket holeis shown. The Voltage pulse starts at point 130 in Fig. 5, when thesprocket hole first enters the area of the apertures, and increasesfairly rapidly to point 131. Here the specular reiiection occurs andresults in sharp peak 132. The reverse process occurs at points 133 and134 on the decreasing amplitude side of the pulse.

Utilizing the known technique of waveform clipping, as by impressing thepulses of Fig. 4 upon the grid of a vacuum tube biased so that all ofthe waveform below the cut off level C.O. is not reproduced in the platecircuit of the tube, it is possible to retain only the peaks 132 in thesignal channel beyond. These are amplified in register gate entity 85 ofFig. l, are gated as has been described, and are employed to control theservo system to exact synchronism with the film through control 87.

Mechanical lateral guidance of the films 9 and 52 is provided by makingthe t of the sprockets to the perforations as precise as possible whilestill allowing the film to enter and leave the sprocket. Also, a smallguide roller 26 is provided at the sound track edge of film-9 and acorresponding one 144 for iilm 52. These are located close to thescanning gate, as 93, for film 52.

On Du Bray-Howell and positive sto cks rounded sprocket holes are notused. Accordingly, I arrange the system for sprocket hole registry shownin either of Figs. 1 or 3 to be rotatable 90 in order to actuate uponthe upper surface of these rectangular perforations. Known mechanicalexpedients are employed to shift the position of the registry opticalsystem with respect to the image scanning gate in this rotation so thatthe upper left rather than the lower left sprocket hole is used forregistration as required. The separation between apertures 126 and 127,Fig. 4, is also reduced to correspond to the lesser dimension of theperforations vertically than horizontally. This is accomplished byreplacing shield 125 with another having reduced separation or byemploying a two piece shield which overlaps and thus may be adjusted forthe desired spacing between the two apertures. As a desirable -alternatethe two piece shield alone may be rotated and the whole optical systemretained in one orientation, save for slit aperture 117 as used in theoptical system of Fig. 3.

A number of alternate constructions of my electronic printer are usefulin preparing motion picture prints for either theatrical exhibition orfor television.

Instead of one composite color negative or positive film 9 as shown inFig. 1 it may be desirable to read picture area information from threeso-called colorseparation negatives (or positives). This is accomplishedessentially by duplication of facilities. Three lm transport andscanning devices are provided, each having a cathode-ray tube scanner 1,drive 79, etc., sprocket register -83, green image channels 25, 28, 31,34, 37, 44, etc., but the dichroic elements 20, 21 and the other colorchannels are omitted. Monochrome film scanning heads are thus provided.In one of these the green separation iilm is run. The green separationis a black and white film originally exposed through a green filter sothat the visual information corresponds to the green light intensitiesin the scene. This monochrome head thus becomes a source of greenchannel video signals. In another head the r'ed separation lm is run,and in still another the blue separation film is run.

From the electrical standpoint red, green and blue video signals areproduced by this process just the same as though a composite film incolor had been employed for film 9 in the tri-color head of Fig. 1.According to electronic convenience the Video outputs from the threemonochrome heads may be impressed upon the inputs of amplifiers 30, 31and 32, or equivalent preampliiers provided at each head. Oneperforation registry system is employed, on the green separation film,and the other two film transports are run in strict synchronism with itthrough the servo control 87, as though these were the equivalent offilm 52 in the system originally described.

A similar substitution of duplication may be made at the reproducing endof my system. Only one reproducing cathode-ray tube, as 47, is employedfor each film transport 90, 144, 147, etc., and three such transportsare provided. This arrangement allows three color separation films to beproduced from one original film 9.

For printing one black and white reproduction from one black andoriginal only two monochrome heads are required, one for reading and onefor writing. It will be seen that with eight heads all types of printingcan be accomplished; color composite to color composite as shown in Fig.l, color composite to color separations as described, color separationsto color composite, and monochrome to monochrome. `It. might be addedthat color to monochrome can be accomplished by utilizing a compositeoriginal if the only record at hand, or by printing from the greenseparation if available.

In the art, use is often made of internegative films for color work. Byemploying three black and white internegatives the best color renditionis obtained. This is because the gamma of each negative can beseparately controlled. The effect of grain of the silver emulsion isalso reduced. The cost, however, of such processing '15 isk higher thanemploying a tripack negative. Also, a set of negatives are usuallyrequired for making contact prints and another set of diierent exposurefor making prints by optical printing.

In my electronic printer this technique can be accommodated with slightmodiiication and with desirable versatility. An internegative, such asthe current Eastman l#5245, is false-sensitized as to co-lor so thatbest dye rendition can be accomplished in the iinished result. Thismeans, that the blue color is not exposed with blue l light, but withred light, and so on.

Speciically, the blue record is known as the yellow master and printsfrom the blue Video signal through a red ilter, Wratten No. 29, forexample. Thus, the blue signal obtained at photomultiplier 29 in Fig. lis switched over to the red reproducing channel by suitable activationof the blue variable gain and gamma entity 38. Necessary instructionsare provided from tape reader 39 by an appropriately punched'tape andare conveyed over one or more of the wires in multiwire conductor 42 toentity 38. The switch-over is accomplished via conductor 149, connectingbetween entities 38 and 36, the latter being in the normal red channel.The No. 29 lter replaces the normal red one at 68 in the reproducingcathode-ray tube channel. In `order to provide separate negatives threeseparateheads are provided as has been described yabove'.

The green record is known Aas the magenta master and prints from thegreen video signal through a blue lter, Wrattens Nos. 47B plus a 2B, forexample. The 2B filter removes any ultra-violet light from the phosphorscreen source.

The red record is knownas the cyan master and prints from the red videosignal through a green ltenWrattens Nos. 16 plus 61, for example.Instructions from the tape reader 39- are conveyed to the green variablegain and gamma entity 37 over conductor 4l and the green signal passesfrom entity 37 to entity 38 via conductor 141. Similarly, furtherinstructions from tape'reader 39 are conveyed to the red variable gainand gamma entity 36 over conductor 4t) and the-red signal passesV fromentity 36 to entity 37 via conductor 142. Y

With this same structure and slightly different programming theequivalent of positive masks may be obtained. In order to produce a maskcorresponding to a given primary color for inserting in another colorchannel it is merely necessary to feed a small amplitude of signal fromthe colorv channel required to supply the mask to the other colorchannel to be masked with phase opposition `of the video waveforms. Thisisaccomplished in my printer by utilizing the cross-connections 140,liti, 142V -between the variable gain and gamma entities 36, 37, 38 withtape and card readers 39 and 5, or both of them, programmed to feed thelow amplitude otphase `opposed video signals as required to accomplishthe particular mask or masks desired.

In certain color work a fourth rendition of the picture is made in blackand white. This is combined with the three color records and oftenprovides additional sharpness to the end result. Such rendition has beenemployed in color motion picture lm produced by the Technicolor processand it is also known in the' color printing art.

This eiect` is obtainable in my printer by simply programming the cardand/ or tape readers 5 and 39 to combine a .fratcional amplitude of thevideo signals in the red and green channels in phaseaddition. I havefound that a minus blue lter in original photography creates the mostpleasing rendition for black and white photography. By omitting the bluevideo channel Vin this instance the same eftectiis obtained. For othereffects, of course, other channels may be combined to supply the blackand white rendition.

It will Vbe realized that the gain and the gamma of `each color channelcan be vvaried atwillinrny electronic printer. This makes itpossible toprint from negatives originally exposed for contact printing whileaccomplishing an optical printing process. In othery words, it providesthe flexibility of processing heretofore accomplished only by making anew set of three negatives, dupe negatives,l etc. for different colorbalance without the considerable expense and time required for actuallymaking these lms. This flexibility by means of electronic signal controlis highly valuable in almost every process accomplished with my printerand results in saving intermediate steps. As has been previouslydescribed, any desired control over the gain (overall contrast) and` thegamma (shape of the contrast function within the overall contrast range)can be exerted by appropriately punching the control tape.

In the prior art, various eiects, such as fade out, fade in,superimposition of two pictures and cross fades between two scenes areaccomplished by what is known as the A and B roll method. In this methodan A roll of original film is prepared, also a B roll, both havingscenes desired -in the resulting print. With the A roll in the printer,say, the raw print stock is exposed to a desired footage count and thenthe exposure is progressively reduced to zero, usually over a length offour feet, by the operation of a dissolve shutter in the known printercamera. Subsequently, the raw stock is rewound to a new start mark, theB roll threaded in the printer head and the printer and camera restartedwith an opening of the dissolve shutter at the proper footage count.

In my electronic printer an A -roll is placed on one iilm readingtransport apparatus and the B roll on another. ,The brilliance of thescanning spot on each reading cathode-ray tube, such as l in Fig. 1, isdirectly controllable by a suitable tape in tape reader 39. At theappropriate footage the bias on the reading cathode-ray tube involved isgradually changed from that giving full illumination intensity to zerointensity. A simultaneous inverse control of the bias on the cathode-raytube illuminating the B roll brings the scene from the B roll ontothevraw film to form a lap dissolve. It will be noted that the raw hnneed not be rewound, nor even stopped. Also start and stop commands maybe given to the lm transport mechanisms from the tape reader toautomatically inter-dissolve the scenes.

For accomplishing a superimposition both cathode-ray tubes are operatedwith illumination spots at once, while for a fade to black neithercathode-ray tube is operative. Should visual material from three filmsbe required to be combined this can-be accomplished by merely adding athird reading head, and so on.

It will be appreciated that the versatility of my electronic printerreduces to a minimum the editing and hand manipulation of the iilmsVinvolved.

It is known in the art that about 40% of the negative in a featuremotion picture `or the equivalent must be duped, that is, transferred toduplicate negative in order that various usual and desirable eects maybe added. Some of. these have been treated above with respect to myprinter. A further illustration concerns impressing a title over ascene. This requires a traveling matte which is arranged as follows. Aseparate (matte) lm is made havingV the title in opaque letters with therest of each frame clear lm. This lm is run `in physical contact lwiththe film containing the scene and the raw stock is exposed. The exposureprocess is repeated employing another lm having the title in letters andartistic details as desired in the finished work, the remainder of eachframe of thissecond title lm being opaque.

Rather than rewinding the raw film for the second exposure it will beVunderstood that the two processes may be carried out simultaneously byusing two reading heads and combining the video signals electronicallyas has been previously pointed out.

By arranging that a matte shall change from clear-lm to opaque. film.inn sequence across the frames a hori- V 17. Zontal, vertical,diagonal, etc. wipe can be accomplished.

Accordingly, there is provided in my electronic printer a modificationof the original construction which merely duplicates the drivefacilities shown in connection with the films 9 and/or 52. This allowsboth original film and matte to run in contact together. Two storagereels and two takeup reels are employed, each on known constant torquemotors as has been described. Two rollers 77 and 147 `and two drivesprockets 78 and 92 are provided. These are offset sufiiciently to clearthe respective reels but are close enough -to allow the films to run inContact through the image scanning gates, as 93.

The mattes may be run in contact with the original films only whenelectronic combination of plural visual information is employed and theraw film is not re- Wound. If the raw film is rewound the mattes may berun in contact with the raw film. In general, where the matte is rundepends upon what size of matte may be on hand. In the process ofreducing 35 mm. film to 16 rnm. film for general television release ofan existing feature, a 35 mm. matte would likely be on hand and so thiswould be run with the 35 mm. negative as a composite original film 9. Inother work if only a 16 mm. matte was available it would be run as acomposite w-ith a raw film 52. Partial mattes may be run in conjunctionwith both films 9 and 52 if this is necessary or desirable. In anyevent, the opportunity to electrically mix plural scenes and matteswithout rerunning the raw film Iis a new contribution of my electronicprinter.

In handling Vistavision film a large degree of vertical adjust isrequired from entity 7 to scan the film transverse of its motion andalso applied to the horizontal sweep deliection coils of yoke 2 (nowturned vertical) so that the many longitudinally disposed scanning lineswill be longitudinally displaced according to the travel of the film andtherefore be positioned one above the other within one frame. Thevertical adjust waveform is a sawtooth, having an amplitude equal to thewhole width of one Vistavision frame. This causes the reading or thewriting in my printer to follow with the motion of the film until thetraverse of the whole area of a frame has been completed and then toquickly pass backward with respect to the direction of film travel tostart the next frame. Sawtooth current waveform generators are knownfrom television technology and do not need tto be further described.

In rotating the yoke of each scanning cathode-ray tube for Vistavisionprocessing a limit switch coactive with the actuator (12, etc.) ispreferably employed to accurately limit the travel to 90.

It will be recalled that processing rates considerably below therepetition rate for usual television (60 fields, 30 complete `frames persecond) are preferred in my printer. Relatively fiicker-free images maybe obtained on the monitor cathode-ray tube 94 if slow decay phosphorsare used for the screen of that tube. Such phosphors were developed bythe DuMont organization during the formulation of the United Statesblack and white television standards. This lis reported in the book,Television Standards & Practice (NTSC), D. Fink, McGraw-Hill, 1943, pp.41-44, and also in the report The DuMont Television System, Document148R, Panel l, National Television Systems Committee. Of course, theconventional color cathode-ray tube may be employed and some flickertolerated.

A11 alternate electronic device for scratch elimination, the reboundlimiters 33, 34, 35, is the Schmidt trigger circuit. This waveformdevice gives an average value of signal intensity for a high value ofscratch amplitude and is turned on and turned off by the start and thestop of the high scratch amplitude signal. This circuit is given in theReference Data for Radio Engineers publication of the International Tel.& Tel. Corp., 4th edition, pg. 468, and need not be further describedhere.

It will be understood that while simple converging lenses have beenshown in Fig. l at 19, 73, etc., these may be the multiple elementlenses known to the trade for photographic purposes and which includefiguring for minimum color, spherical and other aberrations.

It is understood that brightness of the images as represented by videosignals may be increased by increasing the amplitude of a feed-in ofblanking signals, formed in horizontal sweep 4 and previously applied tothe grid of cathode-ray tube 1, into the variable gain and gamma entityof any of the color channels shown in Fig. l. This is according to usualtelevision video techniques.

The matter of recording sound upon motion picture film has not beendetailed herein. Particularly in color film processing the sound trackis invariably printed as a separate process. This is so that a metallicsilver sound track will be obtained rather than one in a color dye.picture film and such a dye does not give satisfactory soundreproduction. Such reproducing equipment, either optical or magnetic,may be added to the film transport for original film 9 in order toobtain an electrical signal according to previously recorded sound onfilm information. The sound may also be obtained from separate soundfilm. This may be synchronously run with film 9 or the whole soundprocess of printing accomplished separately after the visual printinghas been completed but before development.

A corresponding optical or magnetic recording head is also attached tothe transport path for film 52, or separately arranged for subsequentprinting, by known methods. A composite sight and sound print is therebyobtained.

Footage counters and similar auxiliaries may be added to my electronicprinter for convenience and refinement as will be understood 'oy thoseskilled in the art.

Electronic means specified herein `include all kinds of electrical meansin which an electron current may be caused to flow. Such means includesolid state devices, transistors, resistive and reactive components aswell as electron fiow in a vacuum as in vacuum tubes.

Still other modifications may be made in the arrangement, size,proportions and shape of the illustrative embodiments shown anddescribed herein. It will be understood that these have been presentedby way of example and that changes therein to fit individualrequirements do not constitute departures from my invention.

Having thus fully described my invention and the manner in which it isto be practiced, I claim:

l. In combination in an electronic printer for film having electronicmeans for converting emulsion opacities upon an original film toelectrical pulses of amplitudes corresponding to said opacities andfurther electronic means for exposing another film according to saidopacities, said further electronic means controlled by said electricalpulses; means for reducing the effect of scratching upon said originalfilm which include an electronic circuit to alter said electricalpulses, said electronic circuit actuated by the high amplitude of eachelectrical pulse representing the low opacity of a scratch for theduration of said high amplitude, said electronic circuit constituted tolimit the high amplitude of each said electrical pulse corresponding tosaid scratch to a lower amplitude; said high amplitude exceeding theamplitude of all electrical pulses which correspond to said emulsionopacities.

2. In combination in an electronic printer for picture strip film havingelectronic means for converting variations of opacity upon an originalfilm to corresponding electrical impulses, electronic means to handlesaid electrical impulses and further electronic means for exposing anunexposed film according to said opacities from said electricalimpulses; means for reducing the visibility of scratches on saidoriginal film upon the completely processed said unexposed film whichinclude a bistable electronic circuit connected to and coactive withsaid elec- A color dye is the final record on a color motion tronicmeans to handle said electrical impulses, said electronic circuitactuated by the abnormally high amplitude of cach electrical impulserepresenting the low opacity. of

a scratch vat the start ofsaid abnormally high amplitude and.de-actuated at the end thereof, said bistable electronic circuitconstituted to limit the abnormally high amplitude of each saidelectrical impulse corresponding to .said scratch to an averageamplitude which makes the repro dution of said scratch less visible inthe completely processed said unexposed lm, said ,abnormally highamplitude being greater than any amplitude of electrical impulsecorresponding to opacities of pictures upon said 3, In combination in an.electronic printerifor motion nicture film having electronic means forconverting the values of transparency forming images upon one said lm to:a .corresponding electrical signal by scanning and further electronic:means for forming upon a second motion picture lm transparency imagescorresponding to said electrical signal; means for altering the value oftransparency upon said .second film corresponding to a scratch upon saidone lm to reduce the visibility of'said scratch which comprises abistable multivibrator, said multivibratorv Clonnected to said ,furtherelectronic means toflimi-t the amplitude of said electrical signal to avalue within the range of those values corresponding .to the images111190.11 said one motion picture iilm, said multivibrator' triggered bythe abnormalV amplitude of said electrical signal gol-Vresponding tosaid scratch to insert a signalcomponent op- Posite to ,said abnormalamplitude to reduce the same, and said multivibrator rendered inactiveby the reduction ofthe original said signal below said abnormalamplitude at tbe end of scanning said scratch.

4. The combination of claim 3 wherein said bistable multivibrator is anEccles-Jordan flip-HOP.

5. The combination of claim 3 wherein said bistable multivibrator is aSchmidt trigger circuit.

References Cited in the file of `this vpatent UNITED STATES PATENTS 202,331,770 Gano 4. Oct. 12., 1943 2,813,925 Farber Nov. 19, 1957v2,813,926 Farber Nov. 19, 1957

